The sun emits a constant stream of radiant energy. The amount of solar energy directed towards the earth equals the energy that might be produced by burning approximately one-half a trillion tons of coal, which is the amount of coal which might be dug in the United States in about one thousand years at the present rate of mining. Enough solar energy falls on the United States every twenty minutes to fill the country's present power needs for approximately one year.
In order to be an effective source of power, solar energy has to be collected, and substantial developmental work has been done with respect to collective solar energy for the purpose of heating and/or air-conditioning constructions. Solar energy has also been used to furnish power for telephone lines, to cook foods, to heat water for swimming pools, to provide heat for testing metals, and so forth.
In general, it is noted that for the purpose of heating constructions, a collector may be mounted, which is directionally oriented, so that maximum solar energy is received. The sun heats water or air circulating through the collector and such heated water is directly used or stored in an insulated tank. Much developmental work has also been done in connection with the interception of solar energy and the collection of such energy for useful purposes and much of this developmental work has resulted in the issuance of patents.
Stella Andrassy discloses, in U.S. Pat. No. 3,022,781, a solar fluid heater unit having two flexible film members secured to each other adjacent their periphery and further secured to each other in pre-selected regions internally of the periphery to provide a serpentine passageway for fluid with the object in mind to provide a solar fluid heater unit which is light in weight, readily collapsed for transportation and storage, and easily and economically fabricated. The layers may be made from two separate pieces of flexible plastic film or from a single flattened tube of flexible plastic film.
Yoshimatsu Okuda discloses, in U.S. Pat. No. 3,029,806, a bag-shaped water tank having a sealed portion at the perimetric edge thereof and formed of two or more sheets of polyvinyl chloride bonded together in such a manner that there is no possibility of an accident occurring as a result of bursting under normal conditions of use as a solar hot water heater. Therein is provided a water supply and discharge port which functions both as the supply inlet for supplying water to the tank, as well as the discharge outlet for the discharge of water therefrom.
E. Konopka discloses, in U.S. Pat. No. 3,868,945, a heat exchanger for warming the water in a swimming pool by solar heat by the use of rectangular sheets of black matte finish flexible film plastic sealed together so as to form a closed perimeter and having an inlet passage and an outlet passage and a sinuous flow path consisting of a plurality of straight parallel elongated flow channels formed between the inlet and the outlet. At a plurality of points along each straight flow channel, the two plastic sections are heat sealed together to form obstacles to the straight flow path, creating zones of turbulence which enhance the efficiency of the heat exchange. Grommet holes are employed to support the heat exchanger on appropriate hangers. A flow diverter valve is provided which includes a plastic T-section incorporating an arm having a leg section adjoining at right angles.
As will appear more fully hereinafter, the above pouch or bag constructions do not develop the advantages of the invention, which, therefore, constitutes an improvement over the known prior art.